The latest medical research on Optometry

The research magnet gathers the latest research from around the web, based on your specialty area. Below you will find a sample of some of the most recent articles from reputable medical journals about optometry gathered by our medical AI research bot.

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Characteristics of Prescreened Patients Who Did Not Participate in the Zoster Eye Disease Study.

Eye Contact Lens

The Zoster Eye Disease Study (ZEDS) is a multicenter randomized clinical trial (RCT) funded by the National Eye Institute aiming to determine the efficacy of suppressive valacyclovir treatment in herpes zoster ophthalmicus (HZO) that enrolled fewer participants than planned (527/780, 67.6%). Understanding reasons for nonparticipation of likely eligible prescreened patients provides insights into patient populations that are not represented by ZEDS and barriers in clinical trials.

In this retrospective cohort study, HZO adults likely eligible for ZEDS with a history of a typical rash and a medical record within the past year of an episode of epithelial or stromal keratitis or iritis were prescreened at activated Participating Clinical Centers from 2017 to 2022 using a standard prescreening log. De-identified data including demographic information, reasons for exclusion because of ineligibility, and patient refusal were retrospectively entered into REDCap and analyzed.

Prescreening logs with reasons for nonconsent (1244/1706, 72.9%) were included in the data set. Patients were excluded from the study (915/1244, 73.6%) because they did not meet all inclusion criteria (619/915, 67.7%) or met an exclusion criterion (296/915, 32.3%). Among the 12 exclusion criteria for the ZEDS study, immunocompromise (76/296, 25.7%) and renal insufficiency (50/296, 16.9%) were most frequently reported. Patient refusal to participate (327/1,244, 26.3%) was common.

The most common reasons for ineligibility were immunocompromise and renal insufficiency. There may be benefits to long-term antiviral use in these populations not captured in ZEDS. A quarter (26.3%) of prescreened patients refused participation, showing the substantial impact of patient preferences on trial participation.

Morphological Features Among Gaussian, Sagittal, and Tangential Curvature Maps in Normal and Keratoconus Eyes Using Anterior Segment Optical Coherence Tomography.

Eye Contact Lens

To investigate and compare the morphological features and differences among Gaussian, Sagittal, and Tangential anterior corneal curvature maps obtained with an anterior segment optical coherence tomographer combined with a Placido disc MS-39 device in keratoconus (KC) and normal eyes.

Prospective, cross-sectional study including 37 KC and 51 healthy eyes. The pattern of astigmatism and maximum keratometry (Kmax), keratometry at the thinnest point (Ktp) and 2 mm diameter (K2mm), and inferior-superior dioptric asymmetry values were obtained and calculated from Gaussian, Tangential, and Sagittal curvature maps using the MS-39 (CSO).

In KC eyes, an asymmetric bowtie pattern was observed in 64.86% (24/37), 64.86% (24/37), and 0% in the Sagittal, Tangential, and Gaussian maps, respectively. In normal eyes, 51.0% (26/51), 51.0% (26/51), and 0% showed a symmetric bowtie pattern in the Sagittal, Tangential, and Gaussian maps, respectively. There was a significant difference for the variables Kmax, Ktp, and K2mm inferior among the Gaussian, Tangential, and Sagittal maps in both normal and KC groups. Sensitivity discriminating between normal and KC eyes was 100%, 97.3%, and 90.9% and specificity was 94.1%, 100%, and 100% for Kmax coming from the Tangential, Gaussian, and Sagittal maps, respectively.

Gaussian maps displayed significantly different morphological features when compared with Sagittal and Tangential maps in normal and KC eyes. Anterior curvature maps from Gaussian maps do not show the morphological pattern of symmetric bowtie in normal eyes nor asymmetric bowtie in KC eyes. Kmax from Gaussian maps are more specific, however less sensitive than Tangential maps in discriminating KC from normal eyes.

Critical appraisal of Australian and New Zealand paediatric vision screening clinical practice guidelines using the AGREE II tool.

Clinical & Exp Optometry

Vision disorders in children impact health-related quality of life, with early detection and intervention improving outcomes and educational performance. Eye health professionals should be aware of paediatric vision screening guidelines and their development to understand the components of local programmes and the differences in sensitivity and specificity between protocols.

High-quality clinical practice guidelines (CPGs) for vision screening enable the early detection of common vision disorders; however, they require rigorous development to ensure optimal accuracy in detecting vision disorders, enabling timely interventions. This study evaluated the quality of available vision screening CPGs on vision screening of children in Australia and New Zealand.

A systematic search of academic databases, guideline databases, professional associations and Google search engines was conducted to identify relevant paediatric vision screening CPGs. Four independent reviewers used the Appraisal of Guidelines, Research and Evaluation (AGREE II) instrument to assess the quality of individual guidelines and scores were aggregated and reported as the percentage of the total possible score across the six AGREE II domains: scope and purpose, stakeholder involvement, rigour of development, clarity of presentation, applicability, and editorial independence.

Initial 2,999 items were evaluated, with seven guidelines included. AGREE-II quality score agreement ranged from 43.3% to 95.8%. All guidelines scored >60.0% in the scope and purpose, however, most had poor scores of <26.5% in the rigour of development and <3.3% in editorial independence domains. All guidelines recommended screening using measures of habitual distance vision.

Of the guidelines developed for use in Australia and New Zealand, most guidelines scored poorly when assessed against the AGREE II tool, because of lack of editorial independence and rigour of development. Paediatric vision screening guidelines should prioritise systematic review of literature to inform practice and include statements regarding competing interests.

Assessing neophyte response to daily disposable silicone hydrogel contact lenses: A randomised clinical trial investigation over one month.

Ophthalmic and Physiological Optics

This randomised clinical trial assessed the impact on symptoms, tear film dynamics and ocular surface integrity of daily disposable silicone-hydrogel contact lenses (CLs) over a month, paying special attention to lid wiper epitheliopathy (LWE) and its implications for CL discomfort.

Neophyte CL wearers (n = 44, 21.09 ± 5.00 years old) were randomly assigned to either the experimental (n = 24) or control group (n = 20). Participants assigned to the experimental group were required to wear daily disposable CLs for 1 month for at least 8 h/day and 6 days/week. All participants were healthy subjects (no history of ocular surgery or active ocular disease) with spherical refractive errors between -8.00 and +5.00 D and cylindrical power <0.75 D. At the baseline and 1-month sessions, the Dry Eye Questionnaire 5 (DEQ-5) was completed, together with the measurement of tear film osmolarity with the TearLab osmometer, tear meniscus height (TMH) and lipid layer pattern (LLP) using a slit-lamp with Tearscope Plus attached, fluorescein break-up time (FBUT), maximum blink interval (MBI), corneal staining with fluorescein under cobalt blue light and LWE with lissamine green under slit lamp and halogen white light.

At the baseline session, LWE showed a negative correlation with DEQ-5 (r = -0.37, p = 0.02). Significant differences in FBUT and LWE (p = 0.04) and a positive correlation between LWE and DEQ-5 (r = 0.49, p = 0.007) were observed at 1 month. Intrasession analysis at 1 month showed significant differences between the experimental and control groups in DEQ-5, FBUT and LWE (all p ≤ 0.02). Intersession analysis in the experimental group showed variations in DEQ-5, FBUT and LWE (all p ≤ 0.02) but no significant variation in the control group (all p ≥ 0.11).

The presence of LWE was significantly correlated with higher symptom values in the DEQ-5. Also, participants in the experimental group presented higher values of LWE after 1 month of CL wear, in comparison with the control group.

Novel Effective Medical Therapy for Acanthamoeba Keratitis.

Eye Contact Lens

To report first clinical use of novel medical treatment for Acanthamoeba keratitis.

Interventional observational case series. Two patients with Acanthamoeba keratitis were unsuccessfully treated with polihexanide (PHMB) 0.02% and propamidine 0.1% for 6 weeks, then all were shifted in a compassionate use of PHMB 0.08% with novel standardized protocol. The postinterventional follow-up of patients was at least 7 months.

PHMB 0.08% eyedrops in a novel standardized protocol improved infection resolution and led to complete healing of the lesion after 4 weeks in the two cases. Corneal opacities and neovascularization decreased slowly, best-corrected visual acuity slightly improved and progressively increased in the further 7 months, and no infection recurrence occurred.

This preliminary report of two cases shows promising response to polihexanide 0.08% lowering drastically the illness duration, with reduced chance of recurrence, and mostly improving patients' quality of life.

Temporal variations in meibomian gland structure-A pilot study.

Ophthalmic and Physiological Optics

To investigate whether there is a measurable change in meibomian gland morphological characteristics over the course of a day (12 h) and over a month.

The study enrolled 15 participants who attended a total of 11 study visits spanning a 5-week period. To assess diurnal changes in meibomian glands, seven visits were conducted on a single day, each 2 h apart. For monthly assessment, participants attended an additional visit at the same time of the day every week for three consecutive weeks. Meibography using the LipiView® II system was performed at each visit, and meibomian gland morphological parameters were calculated using custom semi-automated software. Specifically, six central glands were analysed for gland length ratio, gland width, gland area, gland intensity and gland tortuosity.

The average meibomian gland morphological metrics did not exhibit significant changes during the course of a day or over a month. Nonetheless, certain individual gland metrics demonstrated notable variation over time, both diurnally and monthly. Specifically, meibomian gland length ratio, area, width and tortuosity exhibited significant changes both diurnally and monthly when assessed on a gland-by-gland basis.

Meibomian glands demonstrated measurable structural change over short periods of time (hours and days). These results have implications for innovation in gland imaging and for developing precision monitoring of gland structure to assess meibomian gland health more accurately.

Confidence in low vision rehabilitation and attitudes towards further learning: A survey of UK optometrists.

Ophthalmic and Physiological Optics

Optometrists are well positioned to help expand low vision (LV) services and improve their availability and accessibility. Determinants of participation in LV service provision must be well understood to facilitate successful service expansion. This survey aimed to investigate optometrists' professional confidence in the delivery of LV services and attitudes towards further learning.

An online survey was emailed to a sample of College of Optometrists members. Respondents rated their confidence in different areas of core optometric practice; confidence in LV was compared with confidence in other areas. Respondents also rated their confidence in undertaking multiple tasks involved in LV service delivery and in routine optometric practice; confidence was compared between optometrists who do and do not work in a LV service. Attitudes towards learning more about assessing and supporting patients with a vision impairment (VI) were recorded.

The survey received 451 recorded responses (15.1% response rate). Optometrists who do not work in a LV service reported significantly lower confidence in LV than in other areas of core optometric practice, whereas optometrists who work in a LV service reported significantly higher confidence in LV than in other areas. Additionally, optometrists who do not work in a LV service reported significantly lower confidence in all tasks involved in LV service delivery than optometrists who work in a LV service (p < 0.001 for all tasks). Approximately 80% of respondents were interested in learning more about assessing and supporting patients with a VI.

Optometrists who do not work in a LV service have relatively low confidence in LV, which could contribute to low motivation to participate in LV service provision. There is sizeable interest in learning more about assessing and supporting patients with a VI, which could help to increase motivation to participate in LV service provision.

Peripheral myopic defocus signal affects the efficiency of visual information processing in myopic children.

Ophthalmic and Physiological Optics

Spectacle lenses with peripheral lenslets have shown promise for myopia control by providing peripheral myopic defocus signals. Here, we aimed to investigate the impact of prolonged exposure (>6 months) to peripheral myopic defocus on visual information processing in myopic children.

The study included 30 myopic children who habitually wore spectacle lenses with highly aspherical lenslets (HAL group) and 34 children who habitually wore single-vision (SV group) spectacles. The quick contrast sensitivity function (qCSF) was used to measure contrast sensitivity (CS) under conditions of no or high noise. Both groups were tested with HAL and SV lenses. The perceptual template model was utilised to fit the contrast sensitivity function (CSF) and determine differences in information processing efficiency through internal additive noise ( N add $$ {N}_{\mathrm{add}} $$ ) and perceptual template gain (β).

The areas under the log CSF in the SV group were significantly higher than for the HAL group in both zero-noise conditions with the SV test lens (p = 0.03) and high-noise conditions with the HAL test lens (p = 0.02). For 2 cycle per degree (cpd) stimuli, β was significantly higher in the SV group with the HAL test lens than in the HAL group (p = 0.02), while there was a trend towards a significant difference in β for 6 cpd stimuli (p = 0.07). However, there were no significant differences in N add $$ {N}_{\mathrm{add}} $$ between the two groups, with or without noise interference.

The reduced CS observed in myopic children wearing HAL lenses for 6 months or more may be due to decreased β. This suggests that prolonged use of spectacle lenses with peripheral myopic defocus signals may compromise the central visual system's ability to process additional external noise, resulting in decreased efficiency in visual information processing.

The effect of landing zone toricity on scleral lens fitting characteristics and optics.

Ophthalmic and Physiological Optics

The fit and optical performance of a scleral lens is affected by the alignment of the landing zone with the underlying ocular surface. The aim of this research was to quantify the effect of landing zone toricity upon scleral lens fitting characteristics (rotation and decentration) and optics (lens flexure) during short-term wear.

Scleral lenses with nominal landing zone toricities of 0, 100, 150 and 200 μm were worn in a randomised order by 10 young healthy participants (mean [SD] 24 [7] years) for 30 min, with other lens parameters held constant. Scleral toricity was quantified using a corneo-scleral profilometer, and lens flexure, rotation, and decentration were quantified using over-topography during lens wear. Repeated measures analyses were conducted as a function of landing zone toricity and residual scleral toricity (the difference between scleral and lens toricity) for eyes with 'low' magnitude scleral toricity (mean: 96 μm) and 'high' magnitude scleral toricity (mean: 319 μm).

Toric landing zones significantly reduced lens flexure (by 0.37 [0.21] D, p < 0.05) and lens rotation (by 20 [24]°, p < 0.05) compared with a spherical landing zone. Horizontal and vertical lens decentration did not vary significantly with landing zone toricity. These trends for flexure, rotation, and decentration were also observed for eyes with 'low' and 'high' magnitude scleral toricity as a function of residual scleral toricity.

Landing zones with 100-200 μm toricity significantly reduced lens flexure (by ~62%) and rotation (by ~77%) but not horizontal or vertical lens decentration, compared with a spherical landing zone, when controlling for other confounding variables. The incorporation of a toric landing zone, even for eyes with lower magnitude scleral toricity (~100 μm), may be beneficial, particularly for front surface optical designs.

Artificial Intelligence-Assisted Prescription Determination for Orthokeratology Lens Fitting: From Algorithm to Clinical Practice.

Eye Contact Lens

To explore the potential of artificial intelligence (AI) to assist prescription determination for orthokeratology (OK) lenses.

Artificial intelligence algorithm development followed by a real-world trial. A total of 11,502 OK lenses fitting records collected from seven clinical environments covering major brands. Records were randomly divided in a three-way data split. Cross-validation was used to identify the most accurate algorithm, followed by an evaluation using an independent test data set. An online AI-assisted system was implemented and assessed in a real-world trial involving four junior and three senior clinicians.

The primary outcome measure was the algorithm's accuracy (ACC). The ACC of the best performance of algorithms to predict the targeted reduction amplitude, lens diameter, and alignment curve of the prescription was 0.80, 0.82, and 0.83, respectively. With the assistance of the AI system, the number of trials required to determine the final prescription significantly decreased for six of the seven participating clinicians (all P<0.01). This reduction was more significant among junior clinicians compared with consultants (0.76±0.60 vs. 0.32±0.60, P<0.001). Junior clinicians achieved clinical outcomes comparable to their seniors, as 93.96% (140/149) and 94.44% (119/126), respectively, of the eyes fitted achieved unaided visual acuity no worse than 0.8 (P=0.864).

AI can improve prescription efficiency and reduce discrepancies in clinical outcomes among clinicians with differing levels of experience. Embedment of AI in practice should ultimately help lessen the medical burden and improve service quality for myopia boom emerging worldwide.

Redistribution of Epithelium and Stroma and Their Relationship With Corneal Curvature After 1-Month Cessation of Overnight Orthokeratology.

Eye Contact Lens

To investigate the changes in the thickness of epithelium and stroma and their relationship with corneal curvature following the cessation of overnight orthokeratology for a period of 1 month.

This prospective study consecutively included 20 juveniles (20 right eyes) who had undergone overnight orthokeratology for a minimum of one year and were willing to discontinue the treatment. The study measured and compared epithelial and corneal curvature using optical coherence tomography and Medmont topographer at the first day of cessation and 1 month after cessation. In addition, changes in uncorrected visual acuity and refractive error before and after the cessation of the treatment were analyzed.

The study found a significant increase in the thickness of the epithelium in the central 2-mm area after the cessation of the treatment (t = -4.807, P<0.001). Moreover, the stroma in the paracentral area (2-5 mm) and peripheral area (5-6 mm) showed a general thinning trend (P=0.016, P=0.016). Regarding the correlation analysis, the change in central epithelial thickness (ΔCET) was significantly correlated with the change in paracentral corneal curvature (ΔPCCC) (r=0.610, P=0.007) and the change in peripheral corneal curvature (ΔPCC) (r=0.597, P=0.009). Similarly, the change in central stromal thickness (ΔCST) was significantly correlated with the change in central corneal curvature (ΔCCC) (r=0.500, P=0.035), ΔPCCC (r=0.700, P=0.001), and ΔPCC (r=0.635, P=0.005).

The study found that the corneal remodeling induced by orthokeratology was reversible after the cessation of the treatment. Specifically, changes in the epithelium were found to be more prominent in the central area, while changes in the stroma were more pronounced in the paracentral and peripheral areas. In addition, the study established a significant correlation between central corneal remodeling and changes in curvature.

Microbiological Profile of Culture-Positive Fungal Keratitis.

Eye Contact Lens

To examine the microbiological profile of cases of culture-positive fungal keratitis presenting to a tertiary eye care center in eastern India.

Microbiology records of all culture-positive microbial keratitis patients presenting to L V Prasad Eye Institute, Bhubaneswar, between January 2020 and December 2021, were retrospectively reviewed. Collected data included smear results of culture-positive fungal or mixed infections, the species isolated, and the time taken for organisms to grow in each media.

Fungal keratitis formed 36% of all culture-positive microbial keratitis, whereas mixed infections (fungi and other organisms) formed 8.5%. The most common fungal species isolated was Fusarium spp. (25.8%). The most common bacteria involved in mixed infection with fungi was Staphylococcus spp. (54.8%). The positivity of potassium hydroxide+calcofluor white stain in detecting fungal filaments was 89.0% and that of Gram stain was 76.1%. Culture-positive cases of fungal keratitis showed most frequent growth on potato-dextrose agar (77.6%). A similar pattern was observed in culture-positive mixed infections (Sabouraud dextrose agar [SDA]: 84%). Most frequent growth of bacteria in mixed infections was seen in thioglycolate broth (54.7%). The shortest time to achieve significant fungal growth was observed in blood agar (BA) and chocolate agar (CA) (2.2/2.3 days, and 1.8/2 days for fungal keratitis and mixed infections, respectively). Filamentous hyaline fungi took the shortest time to achieve significant growth (2.8 days), whereas yeast forms took the longest (5 days).

This study highlights the importance of combined use of both solid and liquid culture media, especially potato dextrose agar (PDA)/SDA and CA, to arrive at a definitive diagnosis of fungal keratitis and possible bacterial co-infection, which forms a significant proportion of cases with fungal keratitis. In resource-poor laboratories, two culture media, either SDA or PDA, along with BA, may be plated to detect mixed infections. Examination of stained smears of corneal samples provides an inexpensive method of rapid diagnosis of fungal keratitis when culture media is not available.